Serving tub



FIG. 1 is a top, front perspective view of a serving tub showing our new design.

FIG. 2 is a front view thereof;

FIG. 3 is a rear view thereof;

FIG. 4 is a right side view thereof;

FIG. 5 is a left side view thereof;

FIG. 6 is a top view thereof; and,

FIG. 7 is a bottom view.

The broken lines indicate optional wood graining of the handles of the serving tub and form no part of the claimed design. 

CLAIM The ornamental design for a serving tub, as shown and described. 